Agriculture 2025 Paper II 50 marks 150 words Compulsory Describe

Q1

Answer the following questions in about 150 words each: (a) Define cell cycle. Describe different types and phases of cell cycle. (10 marks) (b) Briefly discuss significant features of heterosis and explain the dominance and overdominance hypotheses of heterosis, giving their main features. (10 marks) (c) Define Marker-Assisted Selection and give suitable examples. Discuss the applications of marker-assisted selection in recurrent selection, gene pyramiding and QTL introgression. (10 marks) (d) Define 'Grow-out test'. Explain briefly the methods of roguing in seed fields. (10 marks) (e) Classify plant mineral nutrients based on biochemical functions. How do excess minerals in the soil limit the plant growth? (10 marks)

हिंदी में प्रश्न पढ़ें

निम्नलिखित प्रत्येक प्रश्न का उत्तर लगभग 150 शब्दों में दीजिए : (a) कोशिका चक्र को परिभाषित कीजिए। कोशिका चक्र के विभिन्न प्रकारों और चरणों का वर्णन कीजिए। (10 अंक) (b) संकरओज (हेटेरोसिस) की महत्वपूर्ण विशेषताओं की संक्षेप में विवेचना कीजिए तथा संकरओज (हेटेरोसिस) की प्रभाविता (डोमिनेंस) और अति-प्रभाविता (ओवरडोमिनेंस) अवधारणाओं की प्रमुख विशेषताओं को देते हुए व्याख्या कीजिए। (10 अंक) (c) चिह्नक (मार्कर) सहायक चयन को परिभाषित कीजिए तथा उपयुक्त उदाहरण दीजिए। आवर्तक (रिकरेंट) चयन, जीन पिरामिडिंग तथा क्यू टी एल अंतर्क्रमण में चिह्नक (मार्कर) सहायक चयन के अनुप्रयोगों की विवेचना कीजिए। (10 अंक) (d) 'ग्रो-आउट परीक्षण' को परिभाषित कीजिए। बीज प्रक्षेत्रों में रोगिंग की विधियों को संक्षेप में समझाइए। (10 अंक) (e) जैव-रासायनिक कार्यों के आधार पर पादप खनिज पोषक तत्वों को वर्गीकृत कीजिए। मृदा में खनिज तत्वों की अधिकता पादप वृद्धि को कैसे सीमित करती है ? (10 अंक)

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Directive word: Describe

This question asks you to describe. The directive word signals the depth of analysis expected, the structure of your answer, and the weight of evidence you must bring.

See our UPSC directive words guide for a full breakdown of how to respond to each command word.

How this answer will be evaluated

Approach

The directive 'describe' demands detailed, structured exposition of concepts across all five sub-parts. Allocate approximately 30 words (20% time) to each sub-part given equal 10-mark weighting. Structure: concise definition followed by elaboration of types/phases for (a); features then hypothesis comparison for (b); definition-example-applications sequence for (c); definition-methods for (d); and classification-mechanism for (e). No conclusion needed; maximize content density within 150 words per part.

Key points expected

  • (a) Cell cycle: Definition as ordered sequence of events; distinction between mitotic and meiotic cell cycles; phases (G1, S, G2, M) with brief function; mention of G0 phase and checkpoints
  • (b) Heterosis: Definition as hybrid vigour; key features (increased yield, size, fertility, disease resistance); dominance hypothesis (Bruce-Davenport: masking of deleterious recessives) vs overdominance (East-Shull: superior heterozygote at individual loci)
  • (c) MAS: Definition as indirect selection using DNA markers; examples (SSR, SNP markers for disease resistance); applications in recurrent selection (improving population), gene pyramiding (stacking multiple resistance genes), QTL introgression (moving quantitative trait loci)
  • (d) Grow-out test: Definition as field examination of varietal purity; roguing methods (off-type removal based on morphological characters at vegetative, flowering, maturity stages; field standards for Foundation/Certified seed)
  • (e) Mineral nutrients: Biochemical classification (structure constituents, energy storage, enzyme activators, osmotic regulators); excess mineral effects (salinity stress, ion toxicity, nutrient imbalance, osmotic stress reducing water uptake)

Evaluation rubric

DimensionWeightMax marksExcellentAveragePoor
Concept correctness25%12.5Precise definitions for all five sub-parts: cell cycle as sequence of growth and division; heterosis as F1 superiority over parents; MAS as marker-linked trait selection; grow-out test as varietal purity verification; accurate biochemical nutrient classification with correct mineral examplesGenerally correct definitions with minor inaccuracies (e.g., confusing cell cycle phases, oversimplified heterosis explanation, vague MAS description, incomplete roguing stages, or misclassified nutrient functions)Fundamental errors: confusing mitosis/meiosis with cell cycle types, defining heterosis as simply 'hybridization', describing MAS as conventional breeding, equating grow-out test with germination test, or incorrect nutrient classification
Quantitative reasoning15%7.5Numerical specificity where relevant: approximate cell cycle duration mentions, heterosis percentage expressions (e.g., 15-50% yield increase), marker density for MAS, seed certification field standards (e.g., 0.1% off-types for Foundation), critical toxicity concentrations for minerals (e.g., >4 dS/m salinity threshold)General quantitative awareness without precise figures (e.g., 'significant yield increase', 'high marker density', 'low off-type tolerance', 'excess salts harmful')No quantitative dimension; purely qualitative descriptions or incorrect numerical claims (e.g., 100% heterosis expression, single gene control of quantitative traits)
Indian context examples20%10Specific Indian applications: for (b) cite CSH-1/CSH-5 sorghum or maize hybrids; for (c) mention MAS in rice (submergence tolerance Sub1A), wheat (rust resistance), or chickpea (Fusarium wilt); for (d) reference Indian Minimum Seed Certification Standards; for (e) cite Indian saline/alkaline soil problems (e.g., Indo-Gangetic sodic soils)Generic crop mentions without Indian specificity (e.g., 'rice hybrids', 'disease resistance in pulses') or passing reference to Indian agriculture without concrete examplesNo Indian context; exclusively foreign examples (e.g., only US maize hybrids, European wheat programs) or complete omission of geographical specificity
Diagram / process20%10Clear schematic descriptions: for (a) cell cycle diagram with phase transitions and checkpoints; for (b) dominance vs overdominance genetic diagrams; for (c) MAS workflow from DNA extraction to selection; for (d) roguing stage timeline; for (e) nutrient function matrix or toxicity response curve descriptionVerbal description of processes without structural clarity, or mention of 'diagram' without elaborating content; linear lists instead of integrated process descriptionsNo process visualization; purely definitional answers without phase sequences, genetic mechanisms, procedural steps, or systematic classification frameworks
Policy / extension angle20%10Links to seed policy and extension: for (c) mention National Seed Policy 2002, ICAR-NBPGR germplasm conservation, or DAC&FW seed certification; for (d) connect to Seed Act 1966, Seed Rules 1968, or state seed certification agencies; for (e) reference Soil Health Card Scheme, reclamation of alkali soils under CSS, or Fertilizer Control Order for balanced nutritionGeneral awareness of institutional framework (e.g., 'government seed certification', 'soil testing important') without specific policy instruments or schemesNo policy or extension dimension; purely technical answers ignoring regulatory, institutional, or farmer-service aspects of seed quality and soil management

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